Smokers across England are having their final puff at work and the pub before the ban on lighting up in enclosed public places begins at 0600 BST.
Cigarettes will be stubbed out across England on Sunday 1 July
The move, intended to cut deaths from second-hand smoke, brings England into line with the rest of the UK.
Many venues are holding farewell events for the final night of smoking, while local authorities are preparing to enforce the ban.
Anyone lighting up illegally will face a fine of up to £200.
Regulars at the Prince of Wales pub at Hagley, Worcestershire, are having a smokers' party with free cigarettes and a tobacco-themed disco featuring only tobacco-related hits.
And others are coming up with novel solutions for smokers - locals at the Miners Arms in Bristol will be offered fluorescent jackets to go outside and smoke in safety, easily visible to cars.
Landlord Gerry McLoughlin, said: "I chose these jackets because I did not want to put smokers off coming here.
"On a rainy day like today they are just what you need. Rather than spending my money on a new outbuilding I thought I would do this."
But while for some the weekend means a last chance to party, for others the celebrations are only just beginning.
Before the weekend, a public cigarette execution was organised by campaign group Help - For a Life Without Tobacco.
The cigarette was given the chop amid cheers opposite the Tower of London - the place where "enemies of state" traditionally met their fate.
Smokers are making the most of their last chance to party
Meanwhile some are worried that the ban will mean the demise of the traditional pub and other social haunts such as shisha cafes.
And businesses failing to comply with the ban could be hit with fines of up to £1,000 if they fail to put up "no smoking" signs.
Dickie Dawes, from Dinky's Dinah on the A458 near Shrewsbury, told the BBC that his 24-hour cafe would be open when the ban comes in, and that he was preparing early to tell people to stub out their cigarettes.
He said: "At that time in the morning we get quite a lot of revellers who've been out all night clubbing and of course some of them perhaps a bit worse for wear for a little drink.
"So it could be pretty hard tomorrow to sort it out."
The ban is designed to protect people from the effects of secondhand smoke at work, which doctors estimate kills more than 600 people a year.
The government also hopes it will help smokers to quit, and discourage children from taking up the habit.
Meanwhile a legal challenge to the ban has been launched at the High Court.
Freedom To Choose says the change in the law contravenes the European Convention on Human Rights.
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